高集成度四视场中波红外光学系统

Highly Integrated Four Field-of-View MWIR Optical System

为了实现超小型化、长焦距和超大视场,提出并设计了一种高集成度四视场中波红外光学系统。该系统采用双光路结构形式,包括超小视场光路和小/中/大视场光路,两支光路共用中继组;对超小视场光路进行了四次立体折叠,并对小/中/大视场光路进行了二次折叠。通过以上六次折叠,整个双光路光学系统的外形尺寸得到了有效约束,其外形包络在242mm×150mm×85mm(局部125mm)范围内,系统集成度高。这种双光路光学系统包括超小视场、小视场、中视场和大视场四个视场。其中,超小视场的焦距为688mm,视场为0.8°;大视场的焦距为13.19mm,视场为40°,实现了长焦距和超大视场并存,并获得了50×的变倍比;超小视场光学系统仅采用5片透镜,透过率高,并具有光学被动消热差设计;整个双光路光学系统结构紧凑,体积小,实现了超小型化。设计结果表明,该光学系统像质良好,可以满足高性能热像仪的使用要求。

To realize super miniature,long focal length and super wide field-of-view,a highly integrated infrared optical system with four fields of view is proposed and designed.The system adopts a double optical path structure including a super narrow field-of-view optical system and a narrow field-of-view/middle field-of-view/wide field-of-view optical system.The two optical paths share a relay group.The super narrow field-of-view optical system is folded four times in three dimensions.The narrow field-of-view/middle field-of-view/wide field-of-view optical path is folded twice.Through above six folds,the size of the optical system including two optical paths is reduced effectively.Its shape envelope is in the range of 242 mm×150 mm×85 mm(local 125 mm).Thus,the optical system is highly integrated.This double optical path optical system has four fields of view including a super narrow field-of-view,a narrow field-of-view,a middle field-of-view and a wide field-of-view.Among them,the super narrow field-of-view has a focal length of 688 mm and a field-of-view of 0.8 degree.The large field-of-view has a focal length of 13.19 mm and a field-of-view of 40 degree,in which long focal length,super large field-of-view and zoom ratio of 50 are realized.The super narrow field-of-view optical system merely uses five lenses.It has the features of high transmittance and passive optical athermalization design.The whole dual optical path optical system has compact structure and small size and realizes its super miniaturization.The design results show that the image quality of the optical system is good,which meets the requirements of thermal imagers.